1. Field of the Invention
The present invention relates to a camera system comprising: a camera lens assembly that is loaded with an image taking optical system for forming a subject light image and an imaging device that reads the subject light image to generate image data; and a camera body on which the camera lens assembly is detachably mounted, the camera body applying a predetermined image processing to the image data.
2. Description of the Related Art
Hitherto, there is known an interchangeable lens digital camera in which an interchangeable image taking lens is mounted on a camera body incorporating an imaging device. According to the interchangeable lens digital camera, a subject light image formed by an image taking lens is fed to the imaging device provided on the camera body to create photographic image data. Accordingly, it is possible to reuse an interchangeable lens, which is used in a film type of single-lens reflex camera for recording a photographic image on a silver halide film.
However, for example, in the event that a large scale of image taking lens, which is excellent in an optical property, is mounted on a camera main body that incorporates therein a small type of imaging device that is low in resolution, while the image taking lens forms the subject light image with great accuracy, the imaging device cannot read the subject light image with great accuracy. This involves a problem that it is difficult to make the best use of a property of the image taking lens.
In this respect, Japanese Patent Application Laid Open Gazette TokuKai Hei. 8-172561 discloses an interchangeable lens assembly digital camera in which a camera lens assembly incorporating therein an image taking lens and an imaging device is mounted on a camera body. According to the technology disclosed in Japanese Patent Application Laid Open Gazette TokuKai Hei. 8-172561, a provision of CCD suitable for a size of the image taking lens and an optical property in the camera lens assembly beforehand makes it possible to obtain a high picture quality of photographic image through performing photography making the best use of the image taking lens.
In the field of a digital camera, the 35 mm corresponding focal length (a focal length on the 35 mm filmy, a depth of field, and an in-focus range are computed in accordance with a size of an imaging device. A user's confirmation of the 35 mm corresponding focal length makes it possible to recognize a view angle of photography in conversion into a familiar film type of camera. Further, a user's confirmation of the depth of field, and the in-focus range makes it possible to recognize as to what distance range of the subject from the camera can be focused, so that the user can perform photography through focusing to a plurality of subjects mutually different from one another in distance.
However, according to the interchangeable lens assembly digital camera disclosed in Japanese Patent Application Laid Open Gazette TokuKai Hei. 8-172561, the image taking lens and the imaging device are provided on the camera lens assembly in form of a set. Accordingly, when the taking lens is interchanged, the imaging device is together interchanged. Thus, this involves such a problem that a size of the imaging device is greatly changed, and as result, it is impossible to compute the depth of field and the in-focus range.